4
Graphic Controller frequently asked questions
Jan 2003
MB86291 SCARLET AND MB86292 ORCHID QUESTIONS :
Q1:
Is the Scarlet just a "C embedded SDRAM" ?
No ! Scarlet is NOT just the combination of Cremson and SDRAM.
We should be aware about the following major functional upgrade
from Cremson to Scarlet:
(1)Full support geometry processor
Prior to the design of Cremson, our graphics team had participated to develop own geometry
processor devices to be used in arcade game and PC graphics (all interactive 3D graphics
operations). According to the market requirement to accelerate the total 3D graphics operation
(not depending upon the host CPU's floating point computation power), we had determined to
integrate
2 sets of Pinolites with enhanced rendering core into one silicon chip. These Pinolite units are
to handle the entire 3D geometry process (transport, lighting, clipping, screen projection,
triangle set up)
on behalf of host CPU at 1M polygons/sec of sustained performance. Therefore, even if the
burden of the host CPU will be very high, due to all the other operation requirements, still fast
enough
2D/3D operation is performed by the Rose/Scarlet.
(2)Digital video capture and flexible scaling
Video capturing feature was eliminated from Cremson at the very last minute due to the pin
count limit. Now, because of the embedded SDRAM (no more external memory interface), we
have enough pins to assign for digital video input and output. This new module is almost the
same size as display control module of Cremson.
(3)Enhanced Pixel engine and memory interface bus width
Although Cremson offered only 800MBPS of memory bus band, Scarlet is capable to provide
x2 band width. To make a best use of this bus band, drawing unit (DDA,pixel engine, Blt
engine) as well as the memory interface unit were all enhanced, so that Rose/Scarlet can
deliver x5 performance to Cremson.
Considering all the above factors :
Scarlet = 2xG Enhanced Cremson (x5 performance) + Dedicated video
capture/ embedded SDRAM of wide bus band
Therefore the definition of Scarlet is not simply the addition of existing Cremson and
conventional SDRAM devices. Please be aware about this many new function blocks are
integrated to maximize the speed performance (x5 of performance of Cremson).
